The present invention relates to a robot apparatus that coexists with a person and carries out a job in a human life space that is typically represented by a home.
Conventionally, with respect to a safe working method of a robot, most of the systems have a structure in which the entire working space of a robot is completely covered with a cover so that a person and a robot are completely separated from each other so as not to coexist with each other. With respect to the system that permits the coexistence of a person and a working robot, the following prior art apparatuses have been proposed in the industrial robot field (for example, see Japanese Unexamined Patent Publication No. 59-102595, Japanese Unexamined Patent Publication No. 2003-89091, Japanese Unexamined Patent Publication No. 9-185412, and Japanese Unexamined Patent Publication No. 2002-283277.
FIG. 19 shows a conventional robot safety device disclosed in JP 59-102595. In FIG. 19, a safety mat 102 is placed on the periphery of an industrial robot 101. When an operator comes close to the industrial robot 101 to give teaching, an electrode switch of the safety mat 102 is turned ON by the weight of the operator so that an approach of the operator is detected, and the approach of a person is informed to a control apparatus 104 through a cable 103. Upon detection of the approach, the control apparatus 104 slows down the operation speed track to suppress an impact upon contact with the arm of the robot 101 so that a safe teaching operation is achieved.
FIG. 20 shows a conventional robot control device having a touch sensor disclosed in the above-mentioned JP 2003-89091.
In FIG. 20, a robot 111 of a multi-joint arm type is provided with a plurality of touch sensors 113 in its arm portion 112. The robot 111 has a plurality of joints, and depending on jobs, the joints are generally classified into those joints that are directly related to a job and those joints that are not directly related to the job. In the robot 111, with respect to the joint that is not directly related to the job, a weighting process is applied thereto so that, upon detection of a contact by the touch sensor (contact sensor) 113, a departing and avoiding action from the contact portion is conducted, while, with respect to the joint that is directly related to the job, a weighting process is applied thereto so as to give priority to carry out the job. Thus, by providing such a motion component as to depart from the contact portion as a whole, a job that is executed while carrying out an avoiding action is achieved. Here, in FIG. 20, reference numeral 110 represents a visual system, 133 represents a contact control device, 134 represents a job instruction unit, 135 represents a job control device, 136 represents an operation selecting device, 137 represents an operation conversion device, and 138 represents a linear relationship generating device.
FIG. 21 is a block diagram that shows a conventional autonomous moving device described in JP 9-185412.
In FIG. 21, an autonomous moving robot 121 is provided with ultrasonic sensors 122 used for detecting an obstacle in the traveling direction and infrared-ray sensors 123 used for detecting infrared rays radiated from the person. The autonomous moving robot 121 has achieved the following operation: Upon detection of an obstacle by the obstacle sensor 121, it determines whether or not the obstacle is a person by using the infrared-ray sensor 123, and in the case of a person, when, after a predetermined period of stand-by operation, the person does not leave the place, an avoiding operation is carried out. In the case of an obstacle other than a person, it immediately executes an obstacle avoiding operation, and is allowed to move.
Moreover, FIGS. 22A and 22B show a conventional robot safety device described in JP 2002-283277. In FIGS. 22A and 22B, a robot is positioned on the right side 156R of a robot safety device 156. Upon operating the robot, a person pushes a switch 160 so that, as shown in FIG. 22A, a shielding plate 152 on the person side 156L is raised, while a shielding plate 158 on the robot side 156R is lowered. However, when, upon manually exchanging a work 153, a person pushes the switch 160, the shielding plate 158 on the robot side 156R is raised, while the shielding plate 152 on the person side 156L is lowered, as shown in FIG. 22B. In this manner, when the switch 160 is pushed by a person, the shielding plate 158 on the robot side 156R is raised, with the result that the robot is no longer allowed to carry out a job on the work 153 by the shielding plate 158; thus, the job on the work 153 is stopped.
With respect to the robot operation in a specific place typically represented by a factory, such an environment generally allows a robot working space and a human action space to be separable from each other, and a safe operation is easily achieved by completely isolating the robot working space from the human action space by using a cover. Even in the case when portions of the robot working space and the human action space have to be shared, the devices disclosed in JP 59-102595, JP 2003-89091, and JP 9-185412 can be applied so that a safe operation is sufficiently achieved.
However, in a human life environment, typically represented by a home, it is usually difficult to completely separate the life environment into two, that is, the robot working space and the human action space, by using a cover. For example, supposing that a household-choirs assisting operation of a robot in a home, the most portions of the robot working space and the human action space are shared. For this reason, it is difficult to carry out the operation safely by applying the above-mentioned prior art devices disclosed in JP 59-102595, JP 2003-89091, and JP 9-185412, as they are, thereto. The following description will discuss the reasons thereof individually, by typically exemplifying a home.
JP 59-102595 is only effective basically at the time of a teaching instruction-giving operation. It is designed on the assumption that during a normal operation, the robot working space and the human action space are not shared, and a high-speed operation is carried out. The system is designed so that entering of a person into the robot working space is detected by a sensor and the robot is stopped immediately.
However, in the home environment in which most of the robot working space and the human action space are shared, the human action space and the robot working space frequently overlap with each other due to the movement of a person and the movement of a robot. For this reason, when JP 59-102595, as it is, is applied, there is a drawback in that the operation tends to experience failure due to frequent occurrences of a reduction in the operation efficiency due to a low-speed operation and a suspended operation due to a stoppage.
In JP 2003-89091, the contact portion with a person is detected by a contact sensor on the robot arm portion. Based upon the input of the contact sensor, command values are allocated to the respective joints of a robot so that a motion component is prepared so as to depart from the contact portion as the entire robot; thus, the operation is achieved while the contact-avoiding operation is being carried out.
However, in the home environment in which most of the robot working space and the human action space are shared, even when JP 2003-89091, as it is, is applied, upon contact with a person, the robot side only passively takes an avoiding action, with the result that the robot always escapes from the human contact; consequently, it can be said that this system fails to take into consideration that the working space is ensured to accurately carry out an operation. For this reason, although a safe operation with respect to the contact can be achieved to a certain degree, there is a drawback in that the robot operation efficiency for household-choirs assistances or the like is lowered.
In JP 9-185412, upon detection of a person, the autonomous moving device carries out a stand-by process or moves so as to avoid the person.
However, in the home environment in which the most of the robot working space and the human action space are shared, even when JP 9-185412, as it is, is applied, the robot always only passively takes an avoiding action to the person, resulting in an issue in that only the passive action fails to provide a sufficient operation efficiency in the moving operation.
In JP 2002-283277, when, upon placing a work 153, a person pushes the switch 160, the shielding plate 152 (green) on the person side 156L is lowered, while the shielding plate 158 on the robot side 156R is raised, so that the person is allowed to carry out a job of placing the work 153, with the robot operation to the work 153 being stopped. Consequently, even in the event of any failure in the robot, the presence of the shielding plate 158 on the robot side 156R prevents the person from contacting with the robot.
However, in an operation in the home environment in which the most of portions of the robot working space and the human action space are shared, the operation which is carried out with a large shielded space greatly limits the person's action, failing to provide a practical system.
In order to solve the above-mentioned issues of the conventional art, the object of the present invention is to provide a robot apparatus which, even in an environment in which the most of portions of the working space of the robot mechanism unit and the human action space are shared, typically represented by a home, achieves a safe robot operation while ensuring a sufficient operation efficiency.